1 / 44

MRI in Neurology How Physics Makes My life Easier

Richard Simmons, M.D. Child Neurologist Schenectady Neurological Consultants. MRI in Neurology How Physics Makes My life Easier. Today’s Talk. Not about physics Why MRI in Neurology About MRI Neuroanatomy Lesson Examples of normal brain Utility of different sequences

nevan
Download Presentation

MRI in Neurology How Physics Makes My life Easier

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Richard Simmons, M.D. Child Neurologist Schenectady Neurological Consultants MRI in NeurologyHow Physics Makes My life Easier

  2. Today’s Talk • Not about physics • Why MRI in Neurology • About MRI • Neuroanatomy Lesson • Examples of normal brain • Utility of different sequences • How MRI helps make diagnoses (the fun part)

  3. MRI • In 1977, this technology was harnessed to produce the first human MRI scan • Commercial scanning began in the early 1980’s • MRI is now performed thousands of times daily across the world • Neurology is one of the top specialties using MRI

  4. Why MRI in Neurology? • Ultrasound difficult with a thick skull • CT limited by skull thickness • The brain is composed of numerous structures of varying water/lipid/protein content • Vibrant, detailed pictures • NO RADIATION!

  5. The Brain • Complex structure not easily visualized with surgical exploration • Deep structures, brainstem, cranial nerves • Subtle structures not easily visualized with the naked eye • Damage by exploration not easily repaired

  6. Utility of MRI in Neurology • Multiple sequences allow for views of: • Anatomy • Pathology • Blood flow • Arterial • Venous

  7. MRI Basics Hydrogen Protons

  8. In Magnetic Field

  9. RF Pulse

  10. Relaxation Time (T1)

  11. Echo Sequences • Can use 180º RF pulse • Perform repeatedly • Measure time to 63% decay (T2 time)

  12. So What? • Used to measure hydrogen concentration • Water in different environments processes differently • Data collected turned into grayscale image

  13. NORMAL BRAIN

  14. Coronal Axial Sagittal

  15. Crash Course in Neuroanatomy

  16. Neuroanatomy Gray Matter (Neurons) White Matter (Axons with myelin) Cerebrospinal Fluid (CSF)

  17. Neuroanatomy

  18. Neuroanatomy

  19. T1 – “Anatomy” • Presents the brain “as is” • Gray matter is gray • White matter is white • CSF is black

  20. T1 Normal Brain

  21. T2- “Pathology” • Presents the brain “inverted” • Gray matter is white • White matter is gray • CSF is bright white • Emphasizes water-containing areas with greater clarity than T1 • Pathologic lesions frequently have increased water content (edema)

  22. T2 Normal Brain

  23. FLAIR • Fluid Attenuated Inversion Recovery • T2 sequence with CSF signal dropped • Allows better visualization of periventricular pathology • The sequence of choice for Multiple Sclerosis

  24. FLAIR Normal Brain

  25. DWI • Diffusion-Weighted Imaging • Evaluates diffusion of water molecules • Gold standard for evaluating areas of restricted diffusion (stroke) • Very little clinical use otherwise

  26. DWI Normal Brain

  27. Contrast • Gadolinium (Gd) • Rare-earth metal • Paramagnetic • Ideal for visualizing breakdown of the blood-brain barrier

  28. Clinical Cases

  29. Case 1: Weakness • 6 year-old girl • Mild cognitive delay • Gross motor delays since birth • Now with primarily right-sided “clumsiness”

  30. Case 2: Progressive Weakness • 27 year old man • Intermittent loss of strength/sensation that nearly recovers each time • Over time has had progressive weakness of all extremities • Mild cognitive decline

  31. Case 3: Fall with Headache • 5 year-old boy • Fell 5 feet from deck hitting head • CT in the ER was abnormal • Child was physically OK without neurological deficit • MRI to confirm CT findings

  32. Case 4: Partial Seizure • 17 year-old male • Had shaking of right arm for 3 minutes • Mild cognitive disability (IQ 85) • Mild weakness of right side face, arm, and leg • Mild asymmetry of limbs (circumference of right calf less than left calf)

  33. Case 5: New Headaches • 11 year-old girl • 1 month of daily headaches in the right frontal region • Moderate headaches that never really go away • Some episodes of staring off on a daily basis • EEG showed seizure activity in right frontal region

  34. FLAIR Image T1 Image after Gd

  35. Case 6: Right-sided weakness • 72 year-old man • Smoker and frequent alcohol use • High blood pressure • Sudden onset right-sided weakness and difficulty speaking

  36. DWI FLAIR

  37. The Future • Diffusion Tensor Imaging • Water diffuses faster down axons than across axons • Can calculate this speed with DWI • Then create 3D images with directionality to show tracts

  38. Questions?

More Related